A family facing the nightly terror of a bed-bug infestation calls in Imogen, who takes a scientific approach to pest control. Her research reveals what is making the modern bed bug a tougher menace to control than ever before, and she comes up with an ingenious solution to rid the long-suffering family of their parasitic intruders. Elsewhere a case of rats in a smart suburban street leads Deborah on a hunt to find whose garden is harbouring the pests, with surprising results. And a city farm has double trouble with pigeons and rats.